Device and method for controlling the power of a parallel battery pack module

Abstract

Devices and methods for controlling the output of multiple parallel groups of modules are disclosed. In a device for controlling output according to the present invention, a multi-group management unit determines the minimum available output of the first battery group to the nth battery group based on the operating characteristic values of the first battery group to the nth battery group, determines the total output of the multiple parallel groups of modules from the ratio of the total current value to the maximum current value among the minimum available output and the measured current values of the first battery group to the nth battery group, and sends the determined total output to the output management unit, and the output management unit controls the current consumed by the load or the current provided by the charging device to the multiple parallel groups of modules so as not to exceed the total output of the multiple parallel groups of modules.

Description

Technical Field

[0001] The present disclosure relates to a power control device and method, and more particularly, to a power control device and method capable of preventing overcharging or overdischarging of a battery pack having a relatively low resistance in a parallel battery pack module in which a plurality of battery packs are connected in parallel.

[0002] This application claims priority to Korean Patent Application No. 10-2020-0090585, filed in Korea on Jul. 21, 2020, the disclosure of which is incorporated herein by reference. Background Art

[0003] The application fields of batteries are gradually expanding not only to mobile devices such as cellular phones, laptop computers, smartphones, and smart tablets, but also to electric vehicles (EV, HEV, PHEV), large-capacity energy storage systems (ESS), etc.

[0004] A battery module installed in an electric vehicle includes n battery packs connected in parallel to ensure a high energy capacity, and each battery pack includes a plurality of battery cells connected in series. Hereinafter, a module in which n battery packs are connected in parallel will be referred to as a parallel battery pack module.

[0005] In the present specification, a battery cell may include one unit cell or a plurality of unit cells connected in parallel. A battery cell refers to an independent cell having a negative terminal and a positive terminal and being physically separable. For example, one pouch-type lithium polymer cell may be regarded as a unit cell.

[0006] For safety, the total power of the parallel battery pack module is determined based on the battery pack having the lowest available power among the battery packs connected in parallel. That is, the value obtained by multiplying the minimum available power among the available power values of the battery packs by the number of battery packs becomes the total power of the parallel battery pack module.

[0007] For example, in a parallel battery pack module in which five battery packs are connected in parallel, if the available powers of the five battery packs are 1 kW, 2 kW, 3 kW, 4 kW, and 5 kW, respectively, the total power of the parallel battery pack module is 5 × 1 kW (5 kW).

[0008] The management device of the parallel battery pack module provides information on the total power (5 kW) to the control system of the electric vehicle. Then, the control system adaptively distributes the power supplied to the inverter or the DC / DC converter, as well as the power supplied to the ADAS (Advanced Driver Assistance System) unit and the electrical equipment unit that support functions such as lane departure prevention and forward collision warning, so that the power consumed by the electrically driven vehicle does not exceed 5 kW. In this way, the power is distributed within the range of the total power provided by the management device of the parallel battery pack module, which is called the power criterion.

[0009] In addition, when the total power of the parallel battery pack module is P total , according to circuit theory, the group power (P pack,k ) of each battery pack is automatically distributed through the resistance ratio R total between the group resistance (R total ) of the corresponding battery pack and the total resistance (R pack,k ) of the parallel battery pack module. That is, the group power (P k ) of each battery pack is P pack,k × R total / R total / R pack,k . Here, k is the index of the battery pack.

[0010] Since the group power (P pack,k ) is determined not by the available power of the corresponding battery pack but by the total power (P total ) and the resistance ratio R total / R pack,k , as the group resistance (R pack,k ) decreases, the group power (P pack,k ) increases. Therefore, since the group power (P pack,k ) of the battery pack with a low group resistance (R pack,k ) increases within the available power, the corresponding battery pack may be overcharged or over-discharged. Summary of the Invention

[0011] Technical Problem

[0012] The present disclosure is designed to solve the problems of the prior art. Therefore, the present disclosure relates to providing a device and a method for controlling the power of a parallel battery pack module, which can prevent the group power of the battery pack with the lowest resistance from exceeding the available power when determining the total power of the parallel battery pack module, thereby causing overcharging or over-discharging.

[0013] Technical Solution

[0014] In one aspect of the present disclosure, there is provided an apparatus for controlling the power of a parallel battery pack module. The apparatus includes: a first sensor unit to an nth sensor unit configured to measure operation characteristic values including measured current values of a first battery pack to an nth battery pack included in the parallel battery pack module and connected in parallel with each other; a power management unit configured to control the power consumed in a load or the power supplied from a charging device to the parallel battery pack module to correspond to the total power of the parallel battery pack module; and a battery pack management unit operably coupled to the first sensor unit to the nth sensor unit and the power management unit.

[0015] Preferably, the battery pack management unit may be configured to determine the minimum available power of the first battery pack to the nth battery pack based on the operation characteristic values of the first battery pack to the nth battery pack received from the first sensor unit to the nth sensor unit, determine the total power of the parallel battery pack module from the ratio of the total current value to the maximum current value among the minimum available power and the measured current values of the first battery pack to the nth battery pack, and send the determined total power of the parallel battery pack module to the power management unit.

[0016] Preferably, the power management unit may be configured to control the power consumed in the load or the power supplied from the charging device to the parallel battery pack module to correspond to the total power of the parallel battery pack module.

[0017] According to an embodiment, the operation characteristic values may further include measured voltage values of the first battery pack to the nth battery pack. In this embodiment, the battery pack management unit may be configured to: determine the internal resistance of the first battery pack to the nth battery pack from the measured current values and the measured voltage values of the first battery pack to the nth battery pack, refer to a predetermined internal resistance - available power look-up table of each battery pack to determine the available power corresponding to the internal resistance, and determine the minimum value among the available powers as the minimum available power.

[0018] According to another embodiment, the battery pack management unit may be configured to: periodically receive the measured voltage values and measured current values of each battery pack from the first sensor unit to the nth sensor unit, and determine the average ratio of the voltage change to the current change calculated from the measured current values and the measured voltage values of the first battery pack to the nth battery pack by means of linear regression analysis as the internal resistance of the first battery pack to the nth battery pack.

[0019] According to another embodiment, the battery pack management unit may be configured to: determine the state of charge (SOC) of the first battery pack to the nth battery pack based on the operation characteristic values of each battery pack received from the first battery pack to the nth battery pack, determine the available power corresponding to the SOC of the first battery pack to the nth battery pack with reference to a predefined SOC-available power look-up table, and determine the minimum value among the available powers as the minimum available power.

[0020] Preferably, the battery pack management unit may be configured to calculate the total power (P total ) of the parallel battery pack module using the following formula.

[0021] P total = min(P pack,k ) × I total / max(I pack,k )

[0022] (k is an integer in the range from 1 to n; min(P pack,k ) corresponds to the minimum available power among the available powers of the first battery pack to the nth battery pack; I total corresponds to the total current value of the measured current values of the first battery pack to the nth battery pack; and max(I pack,k ) corresponds to the maximum current value among the measured current values of the first battery pack to the nth battery pack.)

[0023] According to another embodiment, the device for controlling the power of the parallel battery pack module according to the present disclosure may further include a communication unit, which is interposed between the battery pack management unit and the power management unit.

[0024] According to still another embodiment, the parallel battery pack module may be installed in an electric vehicle, and the power management unit may be included in the control system of the electric vehicle.

[0025] In another aspect of the present disclosure, there is also provided a battery management system or an electric drive mechanism including the device for controlling the power of the parallel battery pack module as described above.

[0026] In another aspect of the present disclosure, a method for controlling the power of a parallel battery pack module is also provided. The method includes the following steps: (a) providing a first sensor unit to an nth sensor unit, where the first sensor unit to the nth sensor unit are configured to measure operating characteristic values including measured current values of a first battery pack to an nth battery pack included in the parallel battery pack module and connected in parallel with each other; (b) determining the available power of each of the first battery pack to the nth battery pack based on the operating characteristic values of each battery pack received from the first sensor unit to the nth sensor unit; (c) determining the minimum available power among the available powers of the first battery pack to the nth battery pack; (d) determining the total power of the parallel battery pack module from the minimum available power and the ratio of the total current value to the maximum current value among the measured current values of the first battery pack to the nth battery pack; and (e) controlling the charging or discharging of the first battery pack to the nth battery pack to correspond to the total power of the parallel battery pack module.

[0027] According to an embodiment, the operating characteristic values may further include measured voltage values of the first battery pack to the nth battery pack, and step (b) may include: (b1) determining the group resistance of the first battery pack to the nth battery pack from the measured current values and the measured voltage values of the first battery pack to the nth battery pack, (b2) referring to a predetermined group resistance - available power look-up table of each battery pack to determine the available power corresponding to the group resistance, and (b3) determining the minimum value among the available powers as the minimum available power.

[0028] According to another embodiment, step (b) may include: (b1) periodically receiving the measured voltage values and measured current values of each battery pack from the first sensor unit to the nth sensor unit, and (b2) determining the average ratio of the voltage change to the current change calculated from the measured current values and the measured voltage values of the first battery pack to the nth battery pack by linear regression analysis as the group resistance of the first battery pack to the nth battery pack.

[0029] According to still another embodiment, step (b) may include: (b1) determining the SOC of the first battery pack to the nth battery pack based on the operating characteristic values of each battery pack received from the first sensor unit to the nth sensor unit, (b2) referring to a predefined SOC - available power look-up table to determine the available power corresponding to the SOC of the first battery pack to the nth battery pack, and (b3) determining the minimum value among the available powers as the minimum available power.

[0030] Preferably, in step (d), the total power (P) of the parallel battery pack module may be calculated using the following formula total):

[0031] P total = min(P pack,k ) × I total / max(I pack,k )

[0032] (k is an integer within the range from 1 to n; min(P pack,k ) corresponds to the minimum available power among the available powers of the first battery pack to the nth battery pack; I total corresponds to the total current value of the measured current values of the first battery pack to the nth battery pack; and max(I pack,k ) corresponds to the maximum current value among the measured current values of the first battery pack to the nth battery pack.)

[0033] Advantageous Effects

[0034] According to the present disclosure, the total power of the parallel battery pack module is adjusted such that the group power of the battery packs with low resistance among the battery packs included in the parallel battery pack module becomes the same as the minimum available power among the available powers of the battery packs, thereby preventing the battery packs with low resistance from being overcharged or over-discharged. As a result, when the parallel battery pack module is charged or discharged, safety and reliability can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The drawings illustrate preferred embodiments of the present disclosure and are used together with the above disclosure to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not to be construed as limited to the drawings.

[0036] Figure 1 is a block diagram showing the configuration of an apparatus for controlling the power of a parallel battery pack module according to an embodiment of the present disclosure.

[0037] Figure 2 shows an example of a group resistance - available power look-up table according to an embodiment of the present disclosure.

[0038] Figure 3 is a graph showing an example of an I - V distribution when determining the group resistance of a battery pack according to an embodiment of the present disclosure.

[0039] Figure 4 is a flowchart for illustrating a method for controlling the power of a parallel battery pack module according to an embodiment of the present disclosure.

[0040] Figure 5 is a block diagram showing a battery management system including an apparatus for controlling the power of a parallel battery pack module according to an embodiment of the present disclosure.

[0041] Figure 6FIG. 0 is a block diagram of an electric drive mechanism including an apparatus for controlling the power of a parallel battery pack module according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0042] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to the general meaning and dictionary meaning, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle that enables the inventor to define terms suitable for the best explanation. Therefore, the descriptions presented herein are only preferred examples for illustrative purposes only and are not intended to limit the scope of the present disclosure. Thus, it should be understood that other equivalent forms and modifications can be obtained without departing from the scope of the present disclosure.

[0043] In the embodiments described below, a battery cell refers to a lithium secondary battery such as a lithium polymer battery. Here, lithium secondary batteries are collectively referred to as secondary batteries in which lithium ions are used as working ions during charging and discharging to cause an electrochemical reaction at the positive and negative electrodes.

[0044] In addition, even if the name of the secondary battery changes according to the type of electrolyte or separator used in the lithium secondary battery, the type of packaging material for encapsulating the secondary battery, and the internal or external structure of the lithium secondary battery, as long as lithium ions are used as working ions, the secondary battery should be interpreted as being included in the category of lithium secondary batteries.

[0045] The present disclosure can also be applied to other secondary batteries other than lithium secondary batteries. Therefore, any secondary battery to which the technical idea of the present disclosure can be applied should be interpreted as being included in the category of the present disclosure regardless of its type, even if the working ion is not a lithium ion.

[0046] In addition, it should be noted in advance that a battery cell may refer to a single cell or a plurality of cells connected in parallel.

[0047] Figure 1 FIG. 21 is a block diagram showing the configuration of an apparatus (hereinafter, also referred to as a power control apparatus) for controlling the power of a parallel battery pack module according to an embodiment of the present disclosure.

[0048] Refer to Figure 1 , a power control device 10 according to an embodiment of the present disclosure is a device for controlling the power of a parallel battery pack module MP in which a plurality of battery packs P1 to Pn are connected in parallel, and the power control device 10 adaptively controls the total power (P total ) of the parallel battery pack module MP to prevent some battery packs having a relatively low group resistance from being overcharged or overdischarged.

[0049] Preferably, the parallel battery pack module MP may include a first battery pack P1 to an nth battery pack Pn connected in parallel through a first switch unit S1 to an nth switch unit Sn.

[0050] The parallel battery pack module MP may be connected to a load L through an external switch unit M. The external switch unit M includes an external high-potential switch M+ and an external low-potential switch M-. The external high-potential switch M+ and the external low-potential switch M- may be relay switches or power semiconductor switches, but the present disclosure is not limited thereto.

[0051] If the external high-potential switch M+ and the external low-potential switch M- are turned on, the parallel battery pack module MP is electrically connected to the load L. Conversely, when the external high-potential switch M+ and the external low-potential switch M- are turned off, the electrical connection between the parallel battery pack module MP and the load L is released.

[0052] The power control device 10 of the parallel battery pack module MP receives a control command for charging start, charging end, discharging start, or discharging end from a control device that controls the load L, and controls the turning on or off operation of the external switch unit M according to the control command.

[0053] Preferably, the parallel battery pack module MP may be installed in an electric vehicle E, but the present disclosure is not limited thereto. The electric vehicle E refers to a vehicle that can be driven by a motor, such as an electric vehicle, a plug-in hybrid vehicle, or a hybrid vehicle.

[0054] The load L is a device that receives power from the parallel battery pack module MP, and as an example, may be an inverter included in the electric vehicle E. The inverter is a power conversion circuit that is installed at the front end of an electric motor of the electric vehicle E, converts a DC current supplied from the parallel battery pack module MP into a three-phase AC current, and supplies the three-phase AC current to the electric motor.

[0055] The load L may also be a DC / DC converter. The DC / DC converter is a power conversion circuit that converts the voltage of the DC current supplied from the parallel battery pack module MP into a driving voltage of an electrical device unit of the electric vehicle E or a driving voltage of an ADAS, and then applies the converted voltage to the electrical device unit or the ADAS.

[0056] In the present disclosure, the type of the load L is not limited to an inverter or a DC / DC converter, and any device or instrument that can receive power from the parallel battery pack module MP may be included in the category of the load L regardless of its type.

[0057] In the present disclosure, each of the first battery pack P1 to the nth battery pack Pn includes a plurality of battery cells connected in series therein. That is, the first battery pack P1 includes a first battery cell C connected in series 11to the pth battery cell C 1p In addition, the second battery pack P2 includes the first battery cell C connected in series 21 to the pth battery cell C 2p In addition, the third battery pack P3 includes the first battery cell C connected in series 31 to the pth battery cell C 3p In addition, the nth battery pack Pn includes the first battery cell C connected in series n1 to the pth battery cell C np Although the fourth battery pack to the (n - 1)th battery pack are not shown in the figure, they also include p battery cells connected in series in the same manner as the illustrated battery packs.

[0058] Each of the first battery pack P1 to the nth battery pack Pn includes switch units S1 to Sn therein. That is, the first battery pack P1 includes the first switch unit S1. In addition, the second battery pack P2 includes the second switch unit S2. In addition, the third battery pack P3 includes the third switch unit S3. In addition, the nth battery pack Pn includes the nth switch unit Sn. Although the fourth battery pack to the (n - 1)th battery pack are not shown in the figure, they also include switch units in the same manner as the illustrated battery packs.

[0059] Each of the first switch unit S1 to the nth switch unit Sn includes a low - potential switch and a high - potential switch. That is, the first switch unit S1 includes a first high - potential switch S1 installed on the high - potential side of the first battery pack P1 + and a first low - potential switch S1 installed on the low - potential side of the first battery pack P1 - In addition, the second switch unit S2 includes a second high - potential switch S2 installed on the high - potential side of the second battery pack P2 + and a second low - potential switch S2 installed on the low - potential side of the second battery pack P2 - In addition, the third switch unit S3 includes a third high - potential switch S3 installed on the high - potential side of the third battery pack P3 + and a third low - potential switch S3 installed on the low - potential side of the third battery pack P3 - In addition, the nth switch unit Sn includes an nth high - potential switch Sn installed on the high - potential side of the nth battery pack Pn + and an nth low - potential switch Sn installed on the low - potential side of the nth battery pack Pn - In addition, although the fourth battery pack to the (n - 1)th battery pack are not shown in the figure, they also include a high - potential switch and a low - potential switch in the same manner as the illustrated battery packs. In addition, in each switch unit, either the high - potential switch or the low - potential switch can be omitted.

[0060] In the following disclosure, when the switch unit is turned on, the low-potential switch can be turned on first, and the high-potential switch can be turned on later. Additionally, when the switch unit is turned off, the high-potential switch can be turned off first, and the low-potential switch can be turned off later.

[0061] Preferably, the switches used at the first switch unit S1 to the nth switch unit Sn can be relay switches. As an alternative, the first switch unit S1 to the nth switch unit Sn can be semiconductor switches such as MOSFETs or power semiconductor switches, but the present disclosure is not limited thereto.

[0062] The capacitor Cap is provided at the front end of the load L. The capacitor Cap is connected in parallel between the parallel battery pack module MP and the load L. The capacitor Cap functions as a filter to prevent noise current from being applied to the load L or the parallel battery pack module MP.

[0063] The power control device 10 according to the present disclosure includes first current sensors I1 to nth current sensors In. The first current sensors I1 to nth current sensors In are respectively mounted on power lines C1 to Cn connected to the first battery pack P1 to the nth battery pack Pn to measure the current values flowing through the power lines C1 to Cn.

[0064] That is, the first current sensor I1 outputs the measured current value (I pack,1 ) flowing through the first power line C1 included in the first battery pack P1 of the first battery pack P1. Additionally, the second current sensor I2 outputs the measured current value (I pack,2 ) flowing through the second power line C2 included in the second battery pack P2 of the second battery pack P2. Additionally, the third current sensor I3 outputs the measured current value (I pack,3 ) flowing through the third power line C3 included in the third battery pack P3 of the third battery pack P3. Additionally, the nth current sensor In outputs the measured current value (I pack,n ) flowing through the nth power line Cn included in the nth battery pack Pn of the nth battery pack Pn. Although not shown in the figure, the fourth current sensor to the n-1th current sensor respectively output the measured current values flowing through the fourth power line to the n-1th power line included in the fourth battery pack to the n-1th battery pack.

[0065] In the figure, the first current sensors I1 to nth current sensors In are respectively included in the battery packs. However, in the present disclosure, the first current sensors I1 to nth current sensors In can also be mounted outside the battery packs without limitation.

[0066] The first current sensor I1 to the nth current sensor In may be Hall sensors. Hall sensors are known current sensors that output a voltage signal corresponding to the magnitude of the current. In another example, the first current sensor I1 to the nth current sensor In may be sense resistors. If the voltage applied across the sense resistor is measured, Ohm's law can be used to determine the magnitude of the current flowing through the sense resistor. In other words, if the magnitude of the measured voltage is divided by the known resistance value of the sense resistor, the magnitude of the current flowing through the sense resistor can be determined.

[0067] The power control device 10 according to an embodiment of the present disclosure further includes a first voltage sensor V1 to an nth voltage sensor Vn. The first voltage sensor V1 outputs a measured voltage value (V pack,1 ) corresponding to the potential difference between the positive and negative electrodes of the first battery pack P1 of the first battery pack P1. In addition, the second voltage sensor V2 outputs a measured voltage value (V pack,2 ) corresponding to the potential difference between the positive and negative electrodes of the second battery pack P2 of the second battery pack P2. In addition, the third voltage sensor V3 outputs a measured voltage value (V pack,3 ) corresponding to the potential difference between the positive and negative electrodes of the third battery pack P3 of the third battery pack P3. In addition, the nth voltage sensor Vn outputs a measured voltage value (V pack,n ) corresponding to the potential difference between the positive and negative electrodes of the nth battery pack Pn of the nth battery pack Pn. Although not shown in the figure, the fourth voltage sensor to the n-1th voltage sensor respectively output the measured voltage values of the fourth battery pack to the n-1th battery pack.

[0068] The first voltage sensor V1 to the nth voltage sensor Vn include a voltage measurement circuit such as a differential amplifier circuit. Since the voltage measurement circuit is well known in the art, the voltage measurement circuit will not be described in detail here.

[0069] The power control device 10 according to an embodiment of the present disclosure further includes a first temperature sensor T1 to an nth temperature sensor Tn. The first temperature sensor T1 outputs a measured temperature value (T pack,1 ) of the first battery pack P1 indicating the surface temperature of the battery cell located at a predetermined position (e.g., the center) of the first battery pack P1. In addition, the second temperature sensor T2 outputs a measured temperature value (T pack,2 ) of the second battery pack P2 indicating the surface temperature of the battery cell located at a predetermined position (e.g., the center) of the second battery pack P2. In addition, the third temperature sensor T3 outputs a measured temperature value (T pack,3)。 Additionally, the nth temperature sensor Tn outputs a measured temperature value (T of the nth battery pack Pn indicating the surface temperature of the battery cell at a predetermined position (e.g., the center) of the nth battery pack Pn pack,n ). Although not shown in the figure, the fourth temperature sensor to the (n - 1)th temperature sensor respectively output the measured temperature values of the fourth battery pack to the (n - 1)th battery pack.

[0070] In the present disclosure, the first current sensor I1, the first voltage sensor V1, and the first temperature sensor T1 constitute the first sensor unit SU1. Additionally, the second current sensor I2, the second voltage sensor V2, and the second temperature sensor T2 constitute the second sensor unit SU2. Additionally, the third current sensor I3, the third voltage sensor V3, and the third temperature sensor T3 constitute the third sensor unit SU3. Additionally, the nth current sensor In, the nth voltage sensor Vn, and the nth temperature sensor Tn constitute the nth sensor unit SUn. Although not shown in the figure, the fourth sensor unit to the (n - 1)th sensor unit also respectively include a current sensor, a voltage sensor, and a temperature sensor.

[0071] In some cases, it is obvious that the first sensor unit SU1 to the nth sensor unit SUn may further include sensors for measuring other operating characteristics of the battery pack in addition to the sensors for measuring current, voltage, and temperature.

[0072] Preferably, the power control device 10 according to an embodiment of the present disclosure further includes a battery pack management unit 20 operably coupled to the first switch unit S1 to the nth switch unit Sn and the first sensor unit SU1 to the nth sensor unit SUn.

[0073] The battery pack management unit 20 may be operably coupled to the power management unit 40 of the electric vehicle E, and the power management unit 40 manages the power consumed in the load L. As a control element provided in the control system included in the electric vehicle E, the power management unit 40 can adaptively manage the magnitude of the power consumed in the load L to be suitable for the total power of the parallel battery pack modules MP. Here, the total power means the total discharge power of the parallel battery pack modules MP.

[0074] In the present disclosure, the load L may be replaced with a charging device. In this case, the power management unit 40 can adaptively manage the charging power supplied to the parallel battery pack modules MP to be suitable for the total power of the parallel battery pack modules MP. Here, the total power means the total charging power provided to the parallel battery pack modules MP.

[0075] Preferably, the power control device 10 according to an embodiment of the present disclosure may further include a communication unit 30 interposed between the battery pack management unit 20 and the power management unit 40. The communication unit 30 forms a communication interface between the battery pack management unit 20 and the power management unit 40.

[0076] In the present disclosure, any known communication interface that supports communication between two different communication media may be used as the communication interface. The communication interface may support wired or wireless communication. Preferably, the communication interface may support CAN communication, daisy chain communication, RS232 communication, etc.

[0077] If a discharge request is received from the power management unit 40 of the electric vehicle E through the communication unit 30, the battery pack management unit 20 turns on the external switch unit M to start the discharge of the parallel battery pack module MP.

[0078] As a reference, the M+ signal and M- signal output from the battery pack management unit 20 respectively represent signals for controlling the on / off operations of the external high-potential switch M+ and the external low-potential switch M-. In addition, the S1 to Sn signals output from the battery pack management unit 20 represent signals for controlling the on / off operations of the first switch unit S1 to the nth switch unit Sn.

[0079] The battery pack management unit 20 also controls the operations of the current sensors I1 to In, voltage sensors V1 to Vn, and temperature sensors T1 to Tn included in the first sensor unit SU1 to the nth sensor unit SUn while the parallel battery pack module MP is discharging, and periodically records the operation characteristic values of each battery pack received from the current sensors I1 to In, voltage sensors V1 to Vn, and temperature sensors T1 to Tn in the storage unit 50.

[0080] Here, the operation characteristic values include the measured current values (I pack,1 to I pack,n ) of the first battery pack P1 to the nth battery pack Pn as shown in the figure, the measured voltage values (V pack,1 to V pack,n ), and the measured temperature values (T pack,1 to T pack,n ).

[0081] The battery pack management unit 20 may also determine the SOC (state of charge) of each battery pack based on the operation characteristic values of the first battery pack P1 to the nth battery pack Pn.

[0082] For example, the battery pack management unit 20 may measure the current values (I pack,1 to I pack,n)Perform counting to determine the SOC of the first battery pack P1 to the nth battery pack Pn. The battery pack management unit 20 may measure the OCV of each battery pack using the first voltage sensor V1 to the nth voltage sensor Vn before starting the discharge of the first battery pack P1 to the nth battery pack Pn, and determine the initial SOC of each battery pack by referring to the OCV-SOC lookup table to query the SOC corresponding to the OCV. Additionally, the battery pack management unit 20 may count the measured current values (I pack,1 to I pack,n ) of the first battery pack P1 to the nth battery pack Pn over time and record the SOC in the storage unit 50. The OCV-SOC lookup table may be predefined and recorded in the storage unit 50.

[0083] As another example, the battery pack management unit 20 may use an extended Kalman filter to determine the SOC of the first battery pack P1 to the nth battery pack Pn when the parallel battery pack module MP is discharging. That is, the battery pack management unit 20 may determine the SOC of the first battery pack P1 to the nth battery pack Pn by inputting the operating characteristic values of each battery pack received from the first sensor unit SU1 to the nth sensor unit SUn into the extended Kalman filter encoded by software, and record it in the storage unit 50.

[0084] The extended Kalman filter is well-known in the technical field to which the present disclosure pertains. As an example, the extended Kalman filter may be an adaptive algorithm based on an equivalent circuit model or an electrochemical model.

[0085] For example, the SOC estimation using the extended Kalman filter is disclosed in the paper "Extended Kalman filtering for battery management totals of LiPB-based HEV battery packs, Parts 1, 2 and 3" by Gregory L. Plett (Journal of Power Source 134, 2004, pages 252 - 261), and this paper may be incorporated as part of this specification.

[0086] Of course, in addition to the above current counting method or extended Kalman filter, other known methods capable of determining the SOC by utilizing the operating characteristic values of the battery pack may also be used to determine the SOC.

[0087] On the other hand, the battery pack management unit 20 may count the measured current values measured within a specific voltage range among the multiple measured current values of each battery pack recorded in the storage unit 50. In addition, the battery pack management unit 20 may determine the SOH (State of Health) of each battery pack by referring to a current meter value - SOH look-up table, in which the SOH according to the counted current value within a specific voltage range is predefined.

[0088] As another example, the battery pack management unit 20 may adaptively determine the SOH of the first battery pack P1 to the nth battery pack Pn by using an extended Kalman filter when the parallel battery pack module MP is discharging.

[0089] That is, the battery pack management unit 20 may determine the SOH of the first battery pack P1 to the nth battery pack Pn by inputting the operation characteristic values of each battery pack received from the first sensor unit SU1 to the nth sensor unit SUn into an extended Kalman filter encoded by software.

[0090] The SOH estimation using the extended Kalman filter is disclosed in Korean Patent Registration No. 10 - 0818520, titled "Apparatus, method, system and recording medium for estimating a current state and current parameters of an electrochemical cell", which may be incorporated as part of this specification, for example.

[0091] Preferably, the battery pack management unit 20 may determine the internal resistance (R pack,k ; k is the battery pack index) of each battery pack based on the operation characteristic values of the first battery pack P1 to the nth battery pack Pn, and record it in the storage unit 50.

[0092] As an example, the battery pack management unit 20 may determine the I - V distribution of each battery pack by using the multiple measured current values and multiple measured voltage values of each battery pack recorded in the storage unit 50 through linear regression analysis when the parallel battery pack module MP is discharging. Here, based on the current time point, the multiple measured current values and multiple measured voltage values are sampled for the most recent measured values. In addition, the battery pack management unit 20 may determine the slope of the I - V distribution, calculate the absolute value of the slope as the internal resistance (R pack,k ) of each battery pack, and record it in the storage unit 50. The slope of the I - V distribution is the average ratio of the voltage change to the current change, and is a factor corresponding to the resistance according to Ohm's law.

[0093] As another example, when the parallel battery pack module MP is discharging, the battery pack management unit 20 may refer to the currently measured temperature values and SOCs of the respective battery packs recorded in the storage unit 50 to determine the pack resistance (R pack,k ) corresponding to the measured temperature values and SOCs by querying the SOC-temperature-pack resistance look-up table, and record it in the storage unit 50. Here, the SOC-temperature-pack resistance look-up table has a data structure capable of querying the pack resistance corresponding to the SOC and temperature, and the SOC-temperature-pack resistance look-up table may be predefined and recorded in the storage unit 50.

[0094] The battery pack management unit 20 also determines the n available powers (P pack,k ) corresponding to the pack resistance (P pack,k ; k is an integer from 1 to n) of each battery pack by using the predefined correlation information between the pack resistance and the available power, and determines the min(P pack,k ) corresponding to the minimum available power among the n available powers.

[0095] Preferably, the predefined correlation may be a pack resistance-available power look-up table capable of querying the available power according to the pack resistance.

[0096] Figure 2 FIG. is a diagram showing an example of a pack resistance-available power look-up table according to an embodiment of the present disclosure.

[0097] Referring to Figure 2 , the pack resistance-available power look-up table has a data structure capable of querying the available power using the pack resistance, and may be predefined and recorded in the storage unit 50. Preferably, the pack resistance-available power look-up table is provided independently according to the temperature of the battery pack. In this case, it can be considered that the available power varies according to the temperature of the battery pack. Preferably, the battery pack management unit 20 may use the measured temperature values of the respective battery packs to identify the pack resistance-available power look-up table to be queried, and use the identified look-up table to determine the available power (P pack,k ) corresponding to the pack resistance (R pack,k ).

[0098] More preferably, the pack resistance-available power look-up table is provided independently for each SOH and temperature of the battery pack. In this case, it can be considered that the available power varies according to the temperature and SOH of the battery pack. Preferably, the battery pack management unit 20 may use the measured temperature values and SOH of the respective battery packs to identify the pack resistance-available power look-up table to be queried, and use the identified look-up table to determine the available power (P pack,k ) corresponding to the pack resistance (R pack,k ) of each battery pack.

[0099] On the other hand, the battery pack management unit 20 can use the I-V distribution generated when determining the internal resistance (R pack,k ) of each battery pack to determine the available power of each battery pack.

[0100] Figure 3 is a diagram showing an example of the I-V distribution according to an embodiment of the present disclosure.

[0101] Referring to Figure 3 , the voltage at the intersection of the I-V distribution and the V-axis is the OCV (open circuit voltage) corresponding to the SOC of the battery pack. The diamond dot markers indicate multiple measured voltage values and multiple measured current values measured when the parallel battery pack module MP is discharging. In addition, the triangle dot markers indicate multiple measured voltage values and multiple measured current values measured when the parallel battery pack module MP is charging. The I-V distribution is a straight line generated by linear regression analysis of multiple measured voltage values and multiple measured current values. When the battery pack is discharging, the measured current value is positive, and when the battery pack is charging, the measured current value is negative. In addition, the absolute value of the slope of the I-V distribution corresponds to the internal resistance (R pack,k ) of the battery pack.

[0102] When the parallel battery pack module MP is discharging, the battery pack management unit 20 can determine that the current value at the intersection of the I-V distribution and the straight line V = V representing the discharge lower limit voltage min is the maximum discharge current (I max,discharge ), and determine V min ×|I max,discharge | as the available power of the battery pack.

[0103] In addition, when the parallel battery pack module MP is charging, the battery pack management unit 20 can determine that, in order to determine the internal resistance (R pack,k ) of each battery pack, the current value at the intersection of the I-V distribution generated and the line V = V representing the charge upper limit voltage max is the maximum charge current (I max,charge ), and determine V min ×|I max,charge | as the available power of the battery pack.

[0104] The battery pack management unit 20 determines the available power (P pack,k ; k is from 1 to n) of the first battery pack P1 to the nth battery pack Pn, then determines the minimum available power among the n available powers, and records it in the storage unit 50.

[0105] The battery pack management unit 20 also adaptively determines the total power of the parallel battery pack module MP such that the internal power of the battery pack with the lowest internal resistance is the same as the minimum available power, and records it in the storage unit 50.

[0106] Specifically, the battery pack management unit 20 can use the following formula 1 to determine the total power (P total ) of the parallel battery pack modules MP.

[0107] <Formula 1>

[0108] P total = min(P pack,k ) × I total / max(I pack,k )

[0109]

[0110] Here, k is an integer from 1 to n.

[0111] n is the number of battery packs.

[0112] P total is the total power of the parallel battery pack modules MP.

[0113] P pack,k is the available power of the k-th battery pack.

[0114] I pack,k is the measured current value of the k-th battery pack.

[0115] I total is the current value of the parallel battery pack modules MP. I total is the total current value obtained by adding all the measured current values (I pack,1 to I pack,n ) of the first battery pack P1 to the n-th battery pack Pn included in the parallel battery pack modules MP.

[0116] max() is a function that returns the maximum value among multiple input variables. Therefore, max(I pack,k ) corresponds to the maximum current value among the measured current values (I pack,1 to I pack,n ) of the first battery pack P1 to the n-th battery pack Pn included in the parallel battery pack modules MP.

[0117] If the total power (P total ) of the parallel battery pack modules MP is determined according to Formula 1, then the actual pack power of the battery pack with the lowest pack resistance (R pack,k ) becomes equal to the minimum available power min(P pack,k ) as described below. Here, the pack power means the actual power that each battery pack can provide when the parallel battery pack modules MP discharge, and it is a factor determined by the ratio of the pack resistance of each battery pack to the total resistance of the parallel battery pack modules MP.

[0118] First, among the factors (terms) of Equation 1, if the denominator and numerator in " total I / max(I pack,k )" are multiplied by "V / {I total ×max(I pack,k )}", this can be expressed as Equation 2 below.

[0119] <Equation 2>

[0120] P total = min(P pack,k )×I total / max(I pack,k )

[0121] = min(P pack,k )×{V / max(I pack,k )} / {V / I total}

[0122] In Equation 2, V is the output voltage of the parallel battery pack module MP, and it can be substantially the same as the measured voltage values (V pack,1 to V pack,n ) of the first battery pack P1 to the nth battery pack Pn when the parallel battery pack module MP is discharging or charging.

[0123] In Equation 2, "V / max(I pack,k )" corresponds to the minimum resistance min(R pack,k ) among the group resistances of the first battery pack P1 to the nth battery pack Pn. This is because when the output voltage of the parallel battery pack module MP is V, the maximum current flows through the battery pack with the minimum resistance. Additionally, "V / I total " corresponds to the total resistance R total of the parallel battery pack module MP. Therefore, Equation 2 can be converted to Equation 3.

[0124] <Equation 3>

[0125] P total = min(P pack,k )×min(R pack,k ) / R total

[0126] R total is the equivalent resistance of the group resistances of the first battery pack P1 to the nth battery pack Pn connected in parallel and corresponds to the total resistance of the parallel battery pack module MP. The group resistances (R pack,k ) of the first battery pack P1 to the nth battery pack Pn and the total resistance R total of the parallel battery pack module MP satisfy Equation 4 below.

[0127] <Equation 4>

[0128]

[0129] In addition, Equation 3 can be converted into Equation 5 below, which includes the total power min(P pack,k )×n of the parallel battery pack modules MP determined according to the prior art.

[0130] <Equation 5>

[0131] P total = min(P pack,k )×min(R pack,k ) / R total

[0132] = [min(P pack,k )×n]×min(P pack,k )×min(R pack,k ) / {[min(P pack,k )×n]×R total}

[0133] = [min(P pack,k )×n]×min(P pack,k ) / max(P pack,k )

[0134] In the second line of Equation 5 above, "min(R pack,k ) / {[min(P pack,k )×n]×R total}" corresponds to the reciprocal of the group power calculated for the battery pack with the lowest resistance among the first battery pack P1 to the nth battery pack Pn.

[0135] This is because the total power of the parallel battery pack modules MP calculated according to the prior art is "min(P pack,k )×n", which is obtained by multiplying the minimum value "min(P pack,k )" among the available powers of the first battery pack P1 to the nth battery pack Pn by the number of battery packs n, and the group power of the battery pack with the lowest resistance corresponds to the value obtained by multiplying the resistance ratio "R total / min(R pack,k )" by the total power "min(P pack,k )×n" calculated using the available power.

[0136] Since the group power of the battery pack with the lowest resistance among the n group powers has the maximum value, "min(R pack,k ) / {[min(P pack,k )×n]×R total}" can be replaced by max(P pack,k ) -1 , as shown at the end of the third line.

[0137] Here, the battery pack power means the actual power of each battery pack when the parallel battery pack modules MP are discharging. It can be obtained by multiplying the total power (P total ) of the parallel battery pack modules MP by the ratio (R pack,k ) of the resistance of each battery pack to the total resistance (R total ) of the parallel battery pack modules MP, i.e., (R total / R pack,k ).

[0138] Referring to Equation 5, the total power (P total ) of the parallel battery pack modules MP determined according to an embodiment of the present disclosure corresponds to the value obtained by multiplying the total power "min(P pack,k )×n" determined from the minimum available power of the first battery pack P1 to the nth battery pack Pn by the attenuation factor (i.e., "min(P pack,k ) / max(P pack,k )"). Here, "min(P pack,k ) / max(P pack,k )" is the relative ratio of the maximum value to the minimum value among the available powers of the first battery pack P1 to the nth battery pack Pn, and thus is always less than 1. Therefore, the total power of the parallel battery pack modules MP determined according to the present disclosure is less than the total power determined from the minimum available power of the first battery pack P1 to the nth battery pack Pn by [min(P pack,k )×n]×[1 - min(P pack,k ) / max(P pack,k )].

[0139] If the group power (P total ) of the battery pack with the lowest group resistance is calculated using the total power (P pack,Rmin ) determined by Equation 5, it is equal to the minimum available power among the available powers of the first battery pack P1 to the nth battery pack Pn in Equation 6. Therefore, it is possible to fundamentally prevent overcharging or over-discharging of the battery pack with the lowest group resistance while the parallel battery pack modules MP are discharging.

[0140] <Equation 6>

[0141] P pack,Rmin =P total ×R total / min(R pack,k )

[0142] ={min(P pack,k )×min(Rpack,k ) / R total}×{R total / min(R pack,k )}

[0143] =min(P pack,k )

[0144] According to the present disclosure, when determining the total power (P total ) of the parallel battery pack module MP according to Equation 1, the pack power (P pack,k ) of the battery pack with the lowest pack resistance (R pack,Rmin ) becomes equal to the minimum available power min(P pack,k ).

[0145] In addition, in Equation 1, since the total power (P total ) of the parallel battery pack module MP is determined by the total current value I of the measured current values (I pack,1 to I pack,n ) of the first battery pack P1 to the nth battery pack Pn and the maximum value max(I total ) of the measured current values (I pack,1 to I pack,n ), and the measured current values (I pack,k to I pack,1 to I pack,n ) are accurately measured by the first current sensor I1 to the nth current sensor In, there is an advantage that the total power (P total ) can be reliably determined by simple calculation.

[0146] Furthermore, in Equation 1, min(P pack,k ) corresponding to the minimum available power of the first battery pack P1 to the nth battery pack Pn can be determined with reference to the SOC-available power look-up table. That is, after determining the SOC of the first battery pack P1 to the nth battery pack Pn, the available power (P pack,k ) corresponding to the SOC of each battery pack can be mapped with reference to the SOC-available power look-up table, and the minimum value among the mapped available powers can be determined as min(P pack,k ). Here, the SOC-available power look-up table is a look-up table capable of mapping the available power according to the first battery pack P1 to the nth battery pack Pn, and can be predefined and pre-recorded in the storage unit 50.

[0147] If min(P pack,k ) is determined with reference to the SOC-available power look-up table, this can replace using the I-V distribution to determine the pack resistance (R pack,k ) of the first battery pack P1 to the nth battery pack Pn and determining the available power (P pack,k ) from the pack resistance (Rpack,k ) processing, thereby reducing the calculation load for determining the minimum available power min(P pack,k ).

[0148] After determining the total power (P total ), the battery pack management unit 20 can send information about the total power (P total ) to the power management unit 40 of the electric vehicle E through the communication unit 30.

[0149] Then, the power management unit 40 controls the charging or discharging of the parallel battery pack module MP such that the power of the parallel battery pack module MP does not exceed the total power (P total ) determined by Equation 1. That is, the power management unit 40 controls the power consumption such that the power consumed in the load L does not exceed the total power (P total ) determined by Equation 1.

[0150] Specifically, the power management unit 40 adaptively allocates the power supplied to the inverter or DC / DC converter corresponding to the load L and the power supplied to the electrical equipment unit and the ADAS (Advanced Driver Assistance System) that supports functions such as lane departure prevention and forward collision warning, so as not to exceed the total power (P total ) of the parallel battery pack module MP.

[0151] In addition, if the load L is replaced with a charging device, the power management unit 40 can adaptively adjust the magnitude of the charging voltage and charging current provided to the parallel battery pack module MP when the parallel battery pack module MP is charging using the charging device, so as not to exceed the total power (P total ) determined by Equation 1.

[0152] Therefore, as in the prior art, it is possible to prevent the battery packs with low resistance among the battery packs of the parallel battery pack module MP from being overcharged or over-discharged.

[0153] In the present disclosure, there is no particular limitation on the type of the storage unit 50 as long as it is a storage medium capable of recording and erasing information. As an example, the storage unit 50 can be a RAM, ROM, EEPROM, register, or flash memory. The storage unit 50 can also be electrically connected to the battery pack management unit 20 through, for example, a data bus, so as to be accessible by the battery pack management unit 20.

[0154] The storage unit 50 also stores and / or updates and / or erases and / or transmits programs including various control logics executed by the battery pack management unit 20 and / or data generated when the control logics are executed, as well as predefined lookup tables and parameters. The storage unit 50 can be logically divided into two or more parts and can be included in the battery pack management unit 20 without limitation.

[0155] In the present disclosure, the battery pack management unit 20 and / or the power management unit 40 may optionally include a processor, an application specific integrated circuit (ASIC), another chipset, logic circuitry, registers, a communication modem, a data processing device, etc. known in the art for performing the above various control logics. Additionally, when the control logic is implemented in software, the battery pack management unit 20 and / or the power management unit 40 may be implemented as a collection of program modules. At this time, the program modules may be stored in a memory and executed by a processor. The memory may be provided inside or outside the processor and connected to the processor through various well-known computer components. Additionally, the memory may be included in the storage unit 50 of the present disclosure. Additionally, the memory refers to a device in which information is stored (regardless of the device type), rather than a specific storage device.

[0156] Additionally, one or more of the various control logics of the battery pack management unit 20 and / or the power management unit 40 may be combined, and the combined control logic may be written into a computer-readable code system and recorded on a computer-readable recording medium. The recording medium is not particularly limited as long as it can be accessed by a processor included in a computer. As an example, the storage medium includes at least one selected from the group consisting of ROM, RAM, registers, CD-ROM, magnetic tape, hard disk, floppy disk, and optical data recording devices. The code scheme may be distributed to networked computers for storage and execution therein. Additionally, programmers in the field to which the present disclosure pertains can easily deduce the functional programs, codes, and code segments for implementing the combined control logic.

[0157] The power control device 10 according to an embodiment of the present disclosure may be included in a battery management system 100 as shown in Figure 5 . The battery management system 100 controls the overall operations related to the charging and discharging of the battery and is a computing system known in the art as a battery management system (BMS).

[0158] Additionally, in addition to the electric vehicle E, the power control device 10 according to an embodiment of the present disclosure may also be installed in various types of electric drive mechanisms 200 as shown in Figure 6 .

[0159] The electric drive mechanism 200 may be a power device movable under the action of electricity such as an electric bicycle, an electric motorcycle, an electric train, an electric ship, and an electric aircraft or an electric tool having a motor such as an electric drill and an electric grinder.

[0160] Figure 4 is a flowchart for illustrating a method for controlling the power of the parallel battery pack module MP according to an embodiment of the present disclosure.

[0161] As Figure 4 shown in, in step S10, the battery pack management unit 20 determines whether the parallel battery pack module MP is in a discharging state. For this purpose, the battery pack management unit 20 can monitor the measured current values (I pack,1 to I pack,n ) measured using the first current sensor I1 to the nth current sensor In. If the measured current values (I pack,1 to I pack,n ) are positive and non-zero, it can be determined that the parallel battery pack module MP is discharging. If the determination result in step S110 is yes, the battery pack management unit 20 proceeds to step S20.

[0162] In step S20, the battery pack management unit 20 controls the first sensor unit SU1 to the nth sensor unit SUn to receive the operating characteristic values of the first battery pack P1 to the nth battery pack Pn from the first sensor unit SU1 to the nth sensor unit SUn, and records them in the storage unit 50.

[0163] In the present disclosure, the operating characteristic values include the measured voltage values (V pack,1 to V pack,n ), measured current values (I pack,1 to I pack,n ), and measured temperature values (T pack,1 to T pack,n ) of each battery pack. Step S30 is carried out after step S20.

[0164] In step S30, the battery pack management unit 20 determines the SOC and SOH of each battery pack. The methods for determining SOC and SOH have been described above. Step S40 is carried out after step S30.

[0165] In step S40, the battery pack management unit 20 respectively determines the internal resistance (R pack,k ) of the first battery pack P1 to the nth battery pack Pn based on the operating characteristic values of each battery pack received from the first sensor unit SU1 to the nth sensor unit SUn.

[0166] Preferably, the battery pack management unit 20 can generate an I-V distribution for a plurality of measured voltage values and a plurality of measured current values sampled at the current time point by means of linear regression analysis, and calculate the internal resistance (R pack,k ) of each battery pack using the slope of the I-V distribution. Step S50 is carried out after step S40.

[0167] In step S50, the battery pack management unit 20 uses the pre-defined correlation between the internal resistance and the available power to determine the available power (P pack,k)The corresponding n available powers (P pack,k ), and determine the minimum available power among the n available powers (min(P pack,k ).

[0168] In the example, the battery pack management unit 20 can use the group resistance - available power lookup table pre - recorded in the storage unit 50 to query the available power (P pack,k ) corresponding to the group resistance (P pack,k ) of each battery pack.

[0169] Preferably, when determining the available power (P pack,k ) of each battery pack, the battery pack management unit 20 can identify the group resistance - available power lookup table corresponding to the measured temperature value and SOH of the corresponding battery pack, and use the identified group resistance - available power lookup table to query the available power (P pack,k ) corresponding to the group resistance (R pack,k ).

[0170] In another example, the battery pack management unit 20 can determine the intersection point of the I - V distribution used when calculating the group resistance (R pack,k ) of each battery pack with the straight line V = V min corresponding to the discharge lower limit value, and determine the maximum discharge current I max,discharge , and determine the value calculated by the formula V = V min ×|I max,discharge | as the available power (P pack,k ).

[0171] In another example, the battery pack management unit 20 can determine the available power (P pack,k ) of each battery pack by using the SOC - available power lookup table of each battery pack to query the available power corresponding to the SOC of each battery pack. The SOC - available power lookup table can be defined according to the SOH and temperature of the battery pack. In this case, the battery pack management unit 20 can identify the SOC - available power lookup table corresponding to the SOH and measured temperature value of each battery pack, and determine the available power of each battery pack with reference to the identified lookup table.

[0172] Step S60 is performed after step S50.

[0173] In step S60, the battery pack management unit 20 determines the total power (P total ) of the parallel battery pack modules such that the group power of the battery pack with the lowest group resistance (R pack,k ) is the same as the minimum available power using Equation 1 above. At this time, the battery pack management unit 20 can use the measured current values (I pack,1 ) of the first battery pack P1 to the nth battery pack Pnpack,n ) the maximum value max(I pack,k ) and the measured current values (I pack,1 to I pack,n ) of the total current value (I total ) to determine the total power (P total ). Since the measured current values (I pack,1 to I pack,n ) can be accurately measured by the first current sensor I1 to the nth current sensor In, the total power (P total ) with attenuation compared to the total power determined by the prior art can be reliably measured. Here, the total power P total has a magnitude attenuated by [min(P pack,k ) × n] × [1 - min(P pack,k ) / max(P pack,k )] compared to the total power calculated according to the prior art. Step S70 is performed after step S60.

[0174] In step S70, the battery pack management unit 20 sends the total power (P total ) of the parallel battery pack module MP to the power management unit 40 of the electric vehicle E through the communication unit 30. Step S80 is performed after step S70.

[0175] In step S80, the power management unit 40 controls the discharge of the parallel battery pack module MP so that the power of the parallel battery pack module MP does not exceed the total power (P total ) determined by Equation 1.

[0176] That is, the power management unit 40 controls the power consumption so that the power consumed in the load L does not exceed the total power (Ptotal) determined by Equation 1.

[0177] Specifically, the power management unit 40 adaptively distributes the power supplied to the inverter or DC / DC converter corresponding to the load L and the power supplied to the electrical equipment unit and the ADAS (Advanced Driver Assistance System) that supports functions such as lane departure prevention and forward collision warning, so as not to exceed the total power (P total ) of the parallel battery pack module MP determined by Equation 1.

[0178] As a result, the conventional problem of overcharging or over-discharging of the battery packs with low resistance among the battery packs of the parallel battery pack module MP during the discharge of the parallel battery pack module MP can be fundamentally prevented.

[0179] Step S90 is performed after step S80.

[0180] In step S90, the battery pack management unit 20 determines whether a preset power adjustment period has elapsed. The power adjustment period is from several tens of milliseconds to several seconds. If the determination result of step S90 is no, the battery pack management unit 20 keeps the process going. Further, if the determination result of step S90 is yes, the battery pack management unit 20 proceeds to step S100.

[0181] In step S100, the battery pack management unit 20 determines whether the parallel battery pack module MP is discharging. For this purpose, the battery pack management unit 20 may monitor the measured current values (I pack,1 to I pack,n ) measured using the first current sensor I1 to the nth current sensor In. If the measured current value is positive and non-zero, it can be determined that the parallel battery pack module MP is discharging.

[0182] If the determination result of step S100 is no, the battery pack management unit 20 ends the execution of the power control method according to the embodiment of the present disclosure. Further, if the determination result of step S100 is yes, the battery pack management unit 20 proceeds to step S20. Accordingly, the processes of recalculating the total power (P total ) of the parallel battery pack module MP and controlling the discharge of the parallel battery pack module MP are repeated so as not to exceed the calculated total power (P total ).

[0183] In addition, the above power control method relates to the case where the parallel battery pack module MP is discharging. However, it will be apparent to those skilled in the art that the present disclosure can also be applied even when the parallel battery pack module MP is being charged using a charging device.

[0184] According to the present disclosure, the total power of the parallel battery pack module is adjusted such that the group power of the battery pack having the lowest resistance among the battery packs included in the parallel battery pack module becomes the same as the minimum available power among the available powers of the battery packs, thereby fundamentally preventing the battery pack with low resistance from being overcharged or over-discharged. As a result, compared with the prior art, the safety and reliability of the parallel battery pack module can be improved.

[0185] In the description of the various exemplary embodiments of the present disclosure, it should be understood that elements referred to as "units" are functionally rather than physically distinguished. Thus, each element may be selectively integrated with other elements, or each element may be divided into sub-elements for effectively implementing control logic. However, it will be apparent to those skilled in the art that if functional identity is confirmed for an integrated element or a separate element, the integrated element or the separate element falls within the scope of the present disclosure.

[0186] The present disclosure has been described in detail. However, it should be understood that the detailed description and the specific examples, although indicating preferred embodiments of the present disclosure, are given by way of illustration only, since various changes and modifications within the scope of the present disclosure will be apparent to those skilled in the art from this detailed description.

Claims

1. An apparatus for controlling the power of a parallel battery pack module, the apparatus comprises: a first sensor unit to an nth sensor unit, the first sensor unit to the nth sensor unit being configured to measure operating characteristic values, the operating characteristic values including measured current values of a first battery pack to an nth battery pack, the first battery pack to the nth battery pack being included in the parallel battery pack module and being connected in parallel with each other, wherein n is an integer greater than 1; a power management unit configured to control the power consumed in a load or provided by a charging device to the parallel battery pack module to correspond to the total power of the parallel battery pack module; and a battery pack management unit operably coupled to the first sensor unit to the nth sensor unit and the power management unit, wherein the battery pack management unit is configured to determine the minimum available power among the n available powers of the first battery pack to the nth battery pack based on the operating characteristic values of the first battery pack to the nth battery pack received from the first sensor unit to the nth sensor unit, determine the total power of the parallel battery pack module from the ratio of the total current value to the maximum current value among the minimum available power and the measured current values of the first battery pack to the nth battery pack, and send information about the determined total power of the parallel battery pack module to the power management unit, and the power management unit is configured to control the power consumed in the load or provided by the charging device to the parallel battery pack module to correspond to the total power of the parallel battery pack module.

2. The apparatus for controlling the power of a parallel battery pack module according to claim 1, wherein, the operating characteristic values further include measured voltage values of the first battery pack to the nth battery pack, and the battery pack management unit is configured to: determine the group resistance of the first battery pack to the nth battery pack from the measured current values and the measured voltage values of the first battery pack to the nth battery pack, refer to a predetermined group resistance - available power look - up table of each battery pack to determine the available power corresponding to the group resistance, and determine the minimum value among the available powers as the minimum available power.

3. The apparatus for controlling the power of a parallel battery pack module according to claim 2, wherein, the battery pack management unit is configured to: periodically receive the measured voltage values and measured current values of each battery pack from the first sensor unit to the nth sensor unit, and determine the average ratio of the voltage change to the current change calculated from the measured current values and the measured voltage values of the first battery pack to the nth battery pack by means of linear regression analysis as the group resistance of the first battery pack to the nth battery pack.

4. The apparatus for controlling the power of a parallel battery pack module according to claim 1, wherein, the battery pack management unit is configured to: Determine the state of charge (SOC) of the first battery pack to the nth battery pack based on the operating characteristic values of each battery pack received from the first sensor unit to the nth sensor unit. Determine the available power corresponding to the SOC of the first battery pack to the nth battery pack with reference to a predefined SOC-available power look-up table, and Determine the minimum value among the available powers as the minimum available power.

5. The apparatus for controlling the power of a parallel battery pack module according to claim 1, wherein, The battery pack management unit is configured to calculate the total power P of the parallel battery pack modules using the following formula total : P total = min(P pack,k ) × I total / max(I pack,k ) k is an integer in the range from 1 to n; min(P pack,k ) corresponds to the minimum available power among the available powers of the first battery pack to the nth battery pack; I total corresponds to the total current value of the measured current values of the first battery pack to the nth battery pack; and max(I pack,k ) corresponds to the maximum current value among the measured current values of the first battery pack to the nth battery pack.

6. The apparatus for controlling the power of a parallel battery pack module according to claim 1, the apparatus further comprises: A communication unit interposed between the battery pack management unit and the power management unit.

7. The apparatus for controlling the power of a parallel battery pack module according to claim 6, wherein, The parallel battery pack module is installed in an electric vehicle, and The power management unit is included in the control system of the electric vehicle.

8. A battery management system comprising the apparatus for controlling the power of a parallel battery pack module according to any one of claims 1-7.

9. An electric drive mechanism comprising the apparatus for controlling the power of a parallel battery pack module according to any one of claims 1-7.

10. A method for controlling the power of a parallel battery pack module, the method comprises the following steps: (a) Provide a first sensor unit to an nth sensor unit, the first sensor unit to the nth sensor unit being configured to measure operating characteristic values including measured current values of a first battery pack to an nth battery pack, the first battery pack to the nth battery pack being included in the parallel battery pack module and connected in parallel with each other, wherein n is an integer greater than 1; (b) Determine the available power of each of the first battery pack to the nth battery pack based on the operating characteristic values of each battery pack received from the first sensor unit to the nth sensor unit; (c) Determine the minimum available power among the available powers of the first battery pack to the nth battery pack; (d) Determine the total power of the parallel battery pack module from the ratio of the total current value to the maximum current value among the minimum available power and the measured current values of the first battery pack to the nth battery pack; and (e) Control the charging or discharging of the first battery pack to the nth battery pack to correspond to the total power of the parallel battery pack module.

11. The method for controlling the power of a parallel battery pack module according to claim 10, wherein, The operating characteristic values further include the measured voltage values of the first battery pack to the nth battery pack, and The step (b) includes: (b1) Determine the internal resistance of the first battery pack to the nth battery pack from the measured current values and the measured voltage values of the first battery pack to the nth battery pack, (b2) Determine the available power corresponding to the internal resistance with reference to a predefined internal resistance-available power look-up table for each battery pack, and (b3) Determine the minimum value among the available powers as the minimum available power.

12. The method for controlling the power of a parallel battery pack module according to claim 11, wherein, the step (b) includes: (b1) Periodically receiving the measured voltage values and measured current values of each battery pack from the first sensor unit to the nth sensor unit, and (b2) Determining the average ratio of the voltage change to the current change calculated from the measured current values and the measured voltage values from the first battery pack to the nth battery pack by means of linear regression analysis as the pack resistance of the first battery pack to the nth battery pack.

13. The method for controlling the power of a parallel battery pack module according to claim 10, wherein, the step (b) includes: (b1) Determining the SOC of the first battery pack to the nth battery pack based on the operating characteristic values of each battery pack received from the first sensor unit to the nth sensor unit, (b2) Referring to a pre-defined SOC-available power look-up table to determine the available power corresponding to the SOC of the first battery pack to the nth battery pack, and (b3) Determining the minimum value among the available powers as the minimum available power.

14. The method for controlling the power of a parallel battery pack module according to claim 10, wherein, In the step (d), the total power P of the parallel battery pack module is calculated using the following formula total :[[]]END]] P total = min(P pack,k ) × I total / max(I pack,k ) k is an integer ranging from 1 to n; min(P pack,k ) corresponds to the minimum available power among the available powers of the first battery pack to the nth battery pack; I total The total current value corresponding to the measured current values of the first battery pack to the nth battery pack; and max(I pack,k ) corresponds to the maximum current value among the measured current values of the first battery pack to the nth battery pack.

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